Issues in the analysis of co-authorship networks

Scientific collaboration is a complex phenomenon that improves the sharing of competences and the production of new scientific knowledge. Social Network Analysis is often used to describe the scientific collaboration patterns defined by co-authorship relationships. Different phases of the analysis of collaboration are related to: data collection, network boundary setting, relational data matrix definition, data analysis and interpretation of results. The aim of this paper is to point out some issues that arise in these different phases, highlighting: (i) the use of local archives versus international bibliographic databases; (ii) the use of different approaches for setting boundaries in a whole-network; (iii) the definition of a co-authorship data matrix (binary and weighted ties) and (iv) the analysis and the interpretation of network measures for co-authorship data. We discuss the different choices that can be made in these phases within an illustrative example on real data which is referred to scientific collaboration among researchers affiliated to an academic institution. In particular, we compare global and actor-level network measures computed from binary and weighted co-authorship networks in different disciplines.     

Supervisors and Presenteeism: How do Supervisors Accommodate and Support Skilled Workers with Chronic Health Concerns?

There is a broad literature linking social support to health, which includes evidence that social support from supervisors is positively associated with worker health. In addition, once workers experience a health concern, supervisors may play a key role in supporting workers, keeping them on the job despite health issues. However, there are few studies that investigate the day-to-day strategies supervisors utilize to support their workers and help them stay on the job despite health concerns. The study presented in this paper addresses this gap. Thirty-two supervisors from three companies were interviewed about their experiences supporting and accommodating skilled workers during flare-ups of a health condition. A grounded theory approach was used to analyze the text data and identify themes. Three key themes emerged from the data: 1) workplace policies provide the structure for mutual problem solving; 2) communication skills and existing relationships increase supervisor effectiveness; and 3) strategies were aimed at individual, interpersonal, and institutional supports. Supervisors regularly interact with workers to support and accommodate episodes of illness or pain. While supervisors employ novel and effective strategies, there is an opportunity to improve the range of strategies, better understand and utilize company policies, and facilitate appropriate communication about worker health concerns.     

How Adult Attachment Styles Relate to Perceived Psychological Contract Breach and Affective Organizational Commitment

The current study examines the relationship between adult attachment style and both perceived psychological contract breach and affective organizational commitment in a sample of college students with employment experience. Attachment style is argued to be an individual difference factor that affects how an individual perceives organizational events based on theory and existing empirical research related to adult attachment style. Individuals with insecure attachment styles were predicted to perceive more psychological contract breach and have lower levels of affective organizational commitment. The results reveal that individuals with higher levels of preoccupied and dismissive attachment styles perceived higher levels of psychological contract breach, and preoccupied attachment style significantly and negatively relates to affective organizational commitment. The relationship between attachment style and psychological contract dimensions was stronger for relational than transactional contract dimensions. Evidence is also found that perceived psychological contract breach mediates the relationship between preoccupied attachment style and affective commitment. Future potential research directions are described. The implications of these findings for managerial practice is discussed.     

Securitization and Banks’ Equity Risk

This research explores the effects of securitization on the market’s perception of banks’ risk exposure between 2002 and 2007. Our results show that, contrary to some prior evidence in the literature, securitizing banks actually had lower systematic betas until 2007. We find no evidence of increasing idiosyncratic risk with securitization. We identify significant structural break in 2007, when securitizing banks experienced jumps in both systematic and idiosyncratic risks. Finally, we confirm the general belief that larger banks tend to have higher systematic risk and lower idiosyncratic risk because of diversification.     

Proving regularity of the minimal probability of ruin via a game of stopping and control

We reveal an interesting convex duality relationship between two problems: (a) minimizing the probability of lifetime ruin when the rate of consumption is stochastic and the individual can invest in a Black–Scholes financial market; (b) a controller-and-stopper problem, in which the controller controls the drift and volatility of a process in order to maximize a running reward based on that process, and the stopper chooses the time to stop the running reward and pays the controller a final amount at that time. Our primary goal is to show that the minimal probability of ruin, whose stochastic representation does not have a classical form as does the utility maximization problem (i.e., the objective’s dependence on the initial values of the state variables is implicit), is the unique classical solution of its Hamilton–Jacobi–Bellman (HJB) equation, which is a non-linear boundary-value problem. We establish our goal by exploiting the convex duality relationship between (a) and (b).     

Co-monotonicity of optimal investments and the design of structured financial products

We prove that, under very weak conditions, optimal financial products on complete markets are co-monotone with the reversed state price density. Optimality is meant in the sense of the maximization of an arbitrary preference model, e.g., expected utility theory or prospect theory. The proof is based on a result from transport theory. We apply the general result to specific situations, in particular the case of a market described by the Capital Asset Pricing Model or the Black–Scholes model, where we derive a generalization of the two-fund-separation theorem and give an extension to APT factor models and structured products with several underlyings. We use our results to derive a new approach to optimization in wealth management, based on a direct optimization of the return distribution of the portfolio. In particular, we show that optimal products can (essentially) be written as monotonic functions of the market return. We provide existence and nonexistence results for optimal products in this framework. Finally we apply our results to the study of bonus certificates, show that they are not optimal, and construct a cheaper product yielding the same return distribution.     

“If I was going to design a chair,the last thing I would look at is a chair”: product analysis and the causes of fixation in students’ design work 11–16 years

Creativity is acknowledged to be important for economic growth and as an everyday life-skill, however several influential reports have suggested that education could do more to harness creative talent. Creative cognition literature suggests the lack of creativity is at least partly the result of ‘fixation’ (difficulty in generating novel ideas due to imagination being ‘structured’ by existing knowledge). This paper focuses on the secondary (students aged 11–16 years) design and technology (D&T) context in the UK. Here we examine whether teacher practice can contribute to fixation by focusing on one specific facet of teacher practice in D&T; the use of product analysis to inform the generation of creative design ideas. Data is drawn from the preliminary phase of a research and intervention project from interviews with D&T teachers (N = 14), students (N = 126) and lesson observations (N = 10) and an analysis of documents and student work. Product analysis is widely used at different points in design projects but, as is shown, in all cases current practice can lead to fixation, as thinking is constrained down specific paths and tasks are at best at procedural rather than comprehension level. The implications of these findings and tentative ways forward for practitioners are discussed.     

Die Auswirkungen der Finanzkrise sowie von Solvency II auf <Emphasis Type="Italic">Insurance-linked Securities</Emphasis>

Der Beitrag stellt Insurance-linked Securities (“ILS”) als Instrument des alternativen Risikotransfers dar und grenzt ILS von anderen Instrumenten des alternativen Risikotransfers ab.     

Do financial variables help predict the state of the business cycle in small open economies? Evidence from Switzerland

We analyze the forecasting ability of financial variables to predict the state of the Swiss business cycle up to eight quarters ahead. Overall, our results suggest that financial variables convey leading information for the prediction of business cycles, even when applied to a small open economy. However, we clearly find that model specifications need to be extended to include variables accounting for external shocks, such as exchange rates or international commodity prices. It also appears that the forecasting contribution of individual variables changes over time. Specifically, in the last two decades, stock market liquidity has replaced the term spread as the best single predictor.